JP2002328420A - Photographing device and operating switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that fine adjustment of zoom speed is difficult, switch durability is poor, and noise such as rubbing sound is generated in zooming when carrying out a zooming operation with a conventional photographing device. SOLUTION: The zoom switch 6 of a photographing device is constituted of: zooming operation parts 11 and 12 to which operating force for the zooming operation is applied; and a strain element 24 the output value of which changes according to operating physical force and the direction of applying the force to these zoom operation parts 11 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus having a zoom switch and an operation switch.

[0002]

2. Description of the Related Art A photographing apparatus such as a video camera is provided with a zoom mechanism for continuously enlarging and reducing the size of a photographed image. A zoom operation using a zoom mechanism is performed by a user (photographer) operating a zoom switch provided on a housing of a video camera or the like with a finger.

The operation section of the zoom switch has, for example, a lever structure. When the switch lever is moved in one direction from a steady position, a zoom mechanism operates so as to enlarge a photographed image, and when the switch lever is moved in the other direction, the zoom mechanism operates. The zoom mechanism operates so as to reduce the captured image.

[0004]

However, the conventional zoom switch of a video camera or the like has a configuration using a variable resistor with a carbon volume.
(1) It is difficult to fix to a specific zoom speed or finely adjust the zoom speed. (2) Low durability. (3) Noise such as rubbing noise generated by the movable contact portion is generated. (4) There is a problem that the structure is easily increased due to the movable structure.

[0005]

According to the present invention, there is provided a photographing apparatus comprising: a zoom operation unit to which an operation force for a zoom operation is applied; an operation force applied to the zoom operation unit; and a direction in which the operation force is applied. And a zoom switch having a distortion element whose output value changes in accordance with.

In the photographing apparatus having the above-described configuration, by using a distortion element for the zoom switch, an output value corresponding to the delicate strength of the operation force can be obtained, so that fine adjustment of the zoom speed and the like becomes easy. In addition, since the distortion element has no movable portion, noise such as a rubbing noise does not occur during zoom operation, and the durability of the switch itself is increased.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 schematically shows an overall image of a photographing apparatus to which the present invention is applied, (A) is a perspective view thereof, and (B).
Is a side view thereof. The illustrated photographing apparatus 1 corresponds to a video camera or the like, and the entire apparatus is covered with a resin housing 2. A lens unit 3 for photographing is provided at the front of the housing 2, and a viewfinder unit 4 serving as a viewing window is provided at the opposite side of the lens unit 3. A power switch 5 is provided at the rear of the housing 2 below the viewfinder 4. The power switch 5 includes a power-on switch 5A and a power-off switch 5B. On the other hand, a zoom switch 6 is provided on one side surface of the housing 2.

FIGS. 2A and 2B show the structure of a zoom switch 6 according to an embodiment of the present invention. FIG. 2A is a plan view perspective view, and FIG. 2B is a side sectional view. In the figure, a switch support 8 made of resin or the like is provided on a base substrate 7 made of sheet metal.
Is provided. The switch support 8 is fixed on the base substrate 7 by a metal fixing plate 9 interposed between the switch support 8 and the base substrate 7. That is, the fixing plate 9 is provided with a plurality of fixing pieces (not shown) bent toward the base substrate 7, and the fixing plate 9 is fixed to the base substrate 7 by the plurality of fixing pieces.
Further, the fixing plate 9 is provided with four fixing pieces 10 which are bent toward the switch support 8 side, and these four fixing pieces 1 are provided.
By 0, the switch support 8 is fixed to the fixing plate 9.

The switch support 8 has a cylindrical portion 1 at its center.
1 are integrally provided. The cylindrical portion 11 is substantially rectangular in plan view, and has both ends in the major axis direction formed in a substantially arc shape. A key top member 12 is mounted on the upper portion of the switch support 8 so as to cover the tubular portion 11. The key top member 12 has a substantially hat shape as a whole, and is mounted on the switch support 8 in a state of being fitted to the tubular portion 11. More specifically, the key top member 1
Hook portions 13 are integrally formed at two locations on the inner peripheral side of the hook 2, and correspondingly, hook concave portions 14 are integrally formed at two locations on the outer side in the longitudinal direction of the cylindrical portion 11. Then, in a state where the hook portion 13 of the key top member 12 is locked in the corresponding hooking concave portion 14 of the tubular portion 11,
The key top member 12 is fixed to the switch support 8 and prevented from falling off. With such a mounting structure,
The switch support 8 and the key top member 12 are integrally formed.

The zoom switch 6 has a built-in push switch (press switch) 15 integrated therewith. This push switch 15 is a push button 1
6, a compression coil spring 20, a rubber-like elastic member 23, a membrane sheet 22, and the like. A long hole 12A is provided through the center of the key top member 12,
A push button 16 made of resin or the like is fitted into the elongated hole 12A. The push button 16 has a pressing operation portion 17, a flange portion 18, and an operating portion 19 integrally, and is supported movably in the central axis direction of the tubular portion 11 of the switch support 8. The pressing operation portion 17 is disposed so as to protrude slightly outside the outer surface of the key top member 12 through the elongated hole 12A. The brim portion 18 is connected to the switch support 8.
The key top member 12 is pressed against the inner surface of the key top member 12 by a compression coil spring 20 incorporated in the cylindrical portion 11. The operating portion 19 is inserted into a circular shaft hole 21 provided in the cylindrical portion 11 of the switch support 8.

Here, on the side of the photographing apparatus 1,
Key top member 1 through hole 2A provided in housing 2
Only the top of 2 protrudes outward. This is to prevent the user from touching the key top member 12 at a position avoiding the push button 16 when the user performs a zoom operation using the zoom switch 6.

On the other hand, a membrane sheet 22 is laminated on the base substrate 7. The membrane sheet 22 has a contact portion (not shown) just below the push button 16, and a rubber-like elastic member 23 is interposed between the contact portion and the operating portion 19. The rubber-like elastic member 23 is a membrane sheet 2
2 is fixed by bonding or the like.

On the bottom surface of the switch support 8, a distortion element 24 made of a thin film resistor is interposed. The distortion element 24 includes four resistance elements 24A, 24B, 24
C, 24D. These four resistance elements 24A, 24B, 24C, and 24D are connected in a bridge shape to form the distortion element 24. The output of the distortion element 24 is drawn out by a flexible cable 25.

In the key switch 6 incorporating the push switch 15 as described above, in a situation where the user's finger does not touch the key top member 12, that is, in a situation where the zoom operation is not performed, the collar portion is biased by the urging force of the compression coil spring 20. 18 is pressed against the key top member 12. In this state, a slight gap is secured between the operating portion 19 of the push button 16 and the rubber-like elastic member 23, and the contact of the membrane sheet 22 is kept open (the push switch 15 is turned off). .

On the other hand, in a situation where the user's finger is touching the key top member 12, that is, in a situation where a zoom operation is performed, the push button 16 is pressed against the urging force of the compression coil spring 20 (see FIG. Pressed state).
In this state, the operating portion 19 of the push button 16 presses the rubber-like elastic member 23, and the contact force of the membrane sheet 22 is kept closed (the push switch 15 is turned on) by this pressing force. Further, when an operation force for a zoom operation is applied to the key top member 12 in this state,
The switch support 8 is distorted by the operating force, and the distortion causes the resistance elements 24A, 24B, 24
C and 24D expand and contract.

That is, for example, when an operation force is applied to the key top member 12 in a direction for enlarging the photographed image, the resistance elements 24A and 24A are controlled according to the operation force and the direction in which the operation force is applied.
4B contracts, and the resistance elements 24C and 24D expand. In this case, the resistance values of the resistance elements 24A and 24B increase, and the resistance values of the resistance elements 24C and 24D decrease. When an operation force is applied to the key top member 12 in a direction to reduce a captured image, the resistance elements 24A and 24B expand according to the operation force and the direction in which the operation force is applied, and the resistance elements 24C and 24C
24D shrinks. In this case, the resistance values of the resistance elements 24A and 24B decrease, and the resistance values of the resistance elements 24C and 24D increase.

Here, the internal circuit of the distortion element 24 and its operating principle will be described with reference to FIGS.
First, as shown in FIG. 3A, four resistance elements 24A, 24B, 24C, and 24D constituting the distortion element 24 are connected in a bridge shape. In this resistance bridge circuit, the output voltage between one output terminal T1 serving as a common connection point between the resistance elements 24A and 24C and the other output terminal T2 serving as a common connection point between the resistance elements 24B and 24D is as shown in FIG.
As shown in (B), when the operation force is not applied to the key top member 12 (equilibrium state), it becomes equal to the reference voltage Vk. From this state, for example, when an operation force for a zoom operation is applied to the key top member 12 from one direction, the voltage value between the output terminals T1 and T2 increases in proportion to this operation force, and the voltage in the other direction ( When an operating force is applied from the opposite direction), the voltage value between the output terminals T1 and T2 decreases in proportion to the operating force.

From this, a zoom mechanism (not shown) according to the output voltage of the distortion element 24 in the zoom switch 6 is provided.
Is operated, the user who operates the photographing apparatus 1 can perform a zoom operation by touching the key top member 12 with a finger and applying an operation force in a predetermined direction. Zoom switch 6 using this distortion element 24
Therefore, (1) fine adjustment of zoom speed and the like becomes easy, (2) noise such as rubbing noise does not occur at the time of zoom operation, and (3) there is no sliding portion, so that durability is excellent.
(4) Since the switch structure is compact, effects such as easy downsizing of the entire set (imaging device) can be obtained.

However, the strain element 24 is susceptible to temperature rise, humidity, and the like, and has a drawback that the output value is apt to change due to such environmental change. If the output value of the distortion element 24 changes due to a change in the environment, the zoom mechanism operates without permission (erroneous operation) even though the user does not perform the zoom operation. As a countermeasure, it is conceivable to adopt a control mode in which the zoom mechanism is operated only when the output value of the distortion element 24 has changed to be equal to or more than a preset threshold value. In such a case, the threshold value is set to an optimum value. It is difficult to do this. That is, if the threshold is set high, the zoom mechanism will not operate even if the user performs a delicate zoom operation, and if the threshold is set low,
Malfunctions of the zoom mechanism due to environmental changes cannot be reliably prevented.

Therefore, in the present embodiment, a control circuit as shown in FIG. 4 is employed as compensation means for compensating for a change in the output value (voltage) of the distortion element 24 due to an environmental change. In FIG. 4, one output terminal T1 of the distortion element 24 is shown.
Is connected to the non-inverting input terminal (+) of the differential amplifier 26, and the other output terminal T2 is connected to the inverting input terminal (-) of the differential amplifier 26.
It is connected to the. The differential amplifier 26 includes a differential amplifier circuit 30 together with a feedback circuit 29 including a resistor 27 and a capacitor 28.
It constitutes. The output of the differential amplifier circuit 30 is input to an A / D port (analog / digital port) 32 of the microprocessor 31. Further, a switch signal (on / off signal) of the push switch 15 is input to the microprocessor 31.

On the other hand, a low-pass filter 33 and a buffer circuit 34 are sequentially connected to the output line of the microprocessor 31. The low-pass filter 33 includes a resistor 35
And a capacitor 36. The buffer circuit 34 includes a buffer amplifier 37 and a resistor 38. The output terminal of the buffer amplifier 37 is connected to the non-inverting input terminal of the differential amplifier 26 via a resistor 38.

The microprocessor 31 outputs a PWM (Pulse Width Modulation) wave whose pulse width is changed according to an input signal (voltage value) to the A / D port 32. This PWM output is converted into a DC value (DC value) by the low-pass filter 33 and then injected as an offset voltage from the buffer circuit 34. This offset voltage is
When the resistance balance of the distortion element 24 is lost due to an environmental change such as temperature and humidity, and the voltage value between the output terminals T1 and T2 changes (drift), the voltage change is applied so as to compensate (cancel) the voltage change. You. By applying the offset voltage, the correction is performed so that the voltage values applied to the non-inverting input and the inverting input of the differential amplifier 26 become equal to each other.

In this control configuration, the microprocessor 31 monitors the on / off state of the push switch 15 when the power switch 5 is turned on or in a steady state after the power switch 5 is turned on. When the push switch 15 is on, that is, when the user's finger is touching the key top member 12 of the zoom switch 6, the output voltage value of the distortion element 24 input through the differential amplifier circuit 30 The zoom mechanism is moved according to the change of the output voltage value (change from the reference voltage Vk), and the zoom speed is multi-step (for example, 8 steps) or stepless (continuous) according to the change amount of the output voltage value of the distortion element 24. To change.

On the other hand, when the push switch 15 is off, that is, when the user's finger is not touching the key top member 12 of the zoom switch 6, the distortion input via the differential amplifier circuit 30 It monitors whether or not the output voltage value of the element 24 has changed. If the output voltage value has changed due to environmental changes such as temperature and humidity, a reset operation is performed when the change amount exceeds a predetermined amount.

In this reset operation, the microprocessor 31 reads the output voltage value of the distortion element 24 at the time when the amount of change exceeds a predetermined amount, and when the voltage value of one output terminal T1 of the distortion element 24 becomes the predetermined voltage. Value, ie, strain element 2
Then, the PWM output value is moved so that the voltage becomes 1/2 of the voltage applied to 4 (so that the bridge circuit formed by the resistors 24A, 24B, 24C, and 24D is in an equilibrium state). At this time, in the microprocessor 31, first, the distortion element 2
4 is read to determine the voltage level. Next, after correcting the PWM output value at each voltage level, the corrected PWM data is output. As a result, an offset voltage corresponding to the PWM output from the microprocessor 31 is applied to the non-inverting input of the differential amplifier 26 to offset the differential output.

Thereafter, the microprocessor 31 continuously monitors the change of the output voltage value of the distortion element 24, and when the change amount of the output voltage value exceeds the predetermined value again, the same reset operation as described above is repeated. When the power switch 5 is turned off, the output voltage value of the distortion element 24 read in the last reset operation is recorded, and when the power switch 5 is turned on next, the recorded output voltage value is recorded. Is used as an initial value of the reset operation.

As described above, the output voltage value of the distortion element 24 is fed back to the microprocessor 31, and the microprocessor 31 outputs P
By performing the WM output and adding the offset voltage,
Even if the output voltage value of the distortion element 24 changes due to environmental changes, the voltage change can be automatically compensated (canceled). Therefore, malfunction of the zoom mechanism due to environmental change can be reliably prevented.

The microprocessor 31 determines whether the change in the output voltage value of the distortion element 24 is caused by a user operation or an environmental change, by determining whether or not the push switch 15 is pressed (whether or not the push switch 15 is on). ) Can be accurately identified. Then, only when the push switch 15 is not pressed, the compensation function for compensating for the change in the output voltage value of the distortion element 24 is activated, so that the malfunction of the zoom due to the environmental change is reliably prevented, and The zoom mechanism can be operated in response to the fine adjustment of the zoom operation. Further, since the correction function only needs to be operated when the push switch 15 is pressed, the correction processing itself can be simplified.

In the above-described embodiment, the push switch 15 is provided integrally with the zoom switch 6. However, in addition to the above, the push switch 15 is provided at a location different from the zoom switch 6, preferably by the user. When performing a zoom operation by using the push switch 15, the push switch 15 may be provided at a position other than the zoom switch 6 where the user's finger or palm hits.

Further, in the above embodiment, an example of application to the zoom switch 6 used in a photographing device such as a video camera has been described. However, the operation switch according to the present invention is a switch for controlling the operation of a control target. For example, game machines, PDAs (Personal Digital Assistanc
e) It can be applied to a wide range of user interfaces such as automobiles and personal computers.

[0032]

As described above, according to the photographing apparatus of the present invention, fine adjustment of the zoom speed and the like can be easily performed by using the distortion element for the zoom switch for the zoom operation. In addition, since the distortion element has no movable part, it is possible to avoid generation of noise (rubbing sound) at the time of a zoom operation and to increase durability of the zoom switch.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an overall image of a photographing apparatus to which the present invention is applied.

FIG. 2 is a diagram illustrating a structure of a zoom switch according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an internal circuit of a distortion element and an operation principle thereof.

FIG. 4 is a control circuit diagram embodying the compensation means.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photographing device, 6 ... Zoom switch, 8 ... Switch support, 12 ... Key top member, 15 ... Press switch, 24
... Strain element, 31 ... Controller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsuaki Otsubo 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 2H044 AE04 DA02 DE01 2H100 AA18 2H101 DD41 5G006 AA01 AZ09 BA03 BB01 BC03

Claims (5)

[Claims] 1. A zoom operation unit to which an operation force for a zoom operation is applied, and a distortion element whose output value changes according to an operation force applied to the zoom operation unit and a direction in which the operation force is applied. A photographing apparatus comprising a zoom switch having the same. 2. The photographing apparatus according to claim 1, further comprising compensating means for compensating a change in an output value of the distortion element due to an environmental change. 3. The apparatus according to claim 2, further comprising: a pressing switch pressed when the operating force is applied to the zoom operation unit, wherein the compensating unit performs the compensating operation only when the pressing switch is pressed. Item 3. An imaging device according to Item 2. 4. The photographing apparatus according to claim 3, wherein the pressing switch is arranged at a portion of the zoom operation unit to which the operation force is applied. 5. An operation unit to which an operation force for controlling an operation of a control target is applied, and a distortion element whose output value changes according to the operation force applied to the operation unit and a direction in which the operation force is applied. And an operation switch comprising: